Hand made maps

[MikeBravo15]

Hallo all,
is there a possibility to share hand-made maps in the xcsoar-data-content section? If yes, can you please describe how to? Thank you for your kind help

[lordfolken]

What would these maps contain, or do differently than the ones we have? If its just an area, we can add it to
https://github.com/XCSoar/xcsoar-data-content/tree/master/data/source/map as a new map via the coordinates.

In general i want maps that are reproducable. The primary problem at this point is that the osm topology we use is very old.
(I'm currently working on this..)

If you have layers or data that you think xcsoar's maps would benefit from, please do share. So it can be integrated.

[MikeBravo15]

Well it depens. I live in area, where OSM data are more than acceptable, but it do not have to be true for the whole world. I created hires and lores handmade maps for Czecho-Slovak region (I cannot enclose them here as file limit is 25MB, maps are 54 for lo-res elevation map/65MB for hi-res ). All the datas are actually OSM based with exception of city limits, which I was not able to obtain from OSM, so I used Sentinel-2 10m land cover time series of the world https://www.esri.com/partners/impact-observatory-a2T5x0000084pJXEAY/sentinel-2-10m-land--a2d5x000005jw9NAAQ. It also contains a new layer for forrests. Problem with this layer is size - for two relativelly small countries it is kinda acceptable to have this layer, but I still had to optimize shapes a lot, but for Germany/France/Poland I guess forrests are too big to get a decent performance. Therefore I believe, that handmade maps with more details for smaller areas are still a vitable option.

[MikeBravo15]

Sentinel data can be obtained here

https://livingatlas.arcgis.com/landcoverexplorer/#mapCenter=14.801%2C50.009%2C9&mode=step&timeExtent=2017%2C2022&year=2022&downloadMode=true

[MikeBravo15]

.xcm files here:
https://ulozto.cz/tam/12bd1a2e-1cdf-49e2-aedc-762f8d549295

[lordfolken]

Thanks for the sentinel link. I was looking for something that would show the proper city layouts.
In OSM i tried to filter for landuse, but its futile. And administrative boundary is treated differently across the globe.

"Therefore I believe, that handmade maps with more details for smaller areas are still a vitable option."
The problem is maintainability. At some point someone is gonna come and say X is broken. (Like the current elbe ticket..)
And then experience over the last 10 years shows that the person that built the thing is no where to be found. And then i will have to invest time in that one use case again.

I'm fine with adding switches in for a forest layer or similar in the map source config. But manually built stuff is always legacy and of no real value.

[lordfolken]

I'm a bit confused by the landsat layer. This seems to be a geotiff dataset, yet you seems to have shapefiles from somewhere?

[MikeBravo15]

I had to convert it from raster to vector via a Polygonize tool (I used QGIS for this). QGIS is opensource - https://github.com/qgis/QGIS so how this tool works can be probably found there and used for processing the geotiff data

[lordfolken]

I use QGIS extensively. Just wasn't clear whether there was a direct data set.

[lordfolken]

https://github.com/lordfolken/xcsoar-mapgen-postgis i have a qgis style in there that should more or less look like an xcsoar map, in connection to a postgis server.
Although the drawing distance configuration isn't yet in there.

[lordfolken]

I did also a lot of experimentation with ogr2ogr https://github.com/lordfolken/mapgen-datagen

[lordfolken]

I don´t know if you have seen this: I have built https://github.com/XCSoar/xcsoar-mapgen-topology which is able to extract various layers of osm data. It also reduces the shapes and polygon count, to a more manageable size.

Inspired by you, i also extracted forests and landuse. However i haven't included them yet in XCSoar, as i find that xcsoar's polygon renderer and especially decluttering mechansims are not ideal.

[Sundown3867]

Thank you for your effort - during my tests I found that XCSoar do not draw holes in polygons. Forrest polygons exported from OSM had a guite a lot of inner polygons a also overlaps. Overlaps are drawn in darker color in XCS (alpha channel utilized)